Is the Difficult-to-Treat (D2T) concept applicable to axial spondyloarthritis?

Difficult-to-Treat Axial Spondyloarthritis: A New Challenge

Axial spondyloarthritis is a common form of chronic inflammatory rheumatic disease in adults, the treatment of which is based on non-pharmacological elements on the one hand, and pharmacological options on the other, such as non-steroidal anti-inflammatory drugs in the first line, followed by biological or targeted synthetic treatments. The therapeutic objective is remission or a low level of disease activity; if this objective is not achieved, the treatment is rotated or changed. Multiple changes is one factor illustrating the inability to achieve disease control and may lead to the notion of a difficult-to-treat disease (D2T). This requires a consensual definition including, beyond the number or therapeutic changes, the assessment of all the dimensions of the disease (objective signs of inflammation, residual pain, degenerative changes, psychosocial context). Recognising D2T patients will enable us to identify a particular population and the factors associated with this condition. When faced with a D2T disease, we need to analyse the causes of treatment failure and take into account the different components of the disease and the patient. In the absence of any prospect of new therapeutic targets in the short term for this disease, patient management may involve intensification of non-pharmacological means and evaluation of new therapeutic strategies such as combinations of targeted treatments.

Can we define difficult-to-treat systemic sclerosis?

INTRODUCTION

Systemic sclerosis (SSc) is a chronic autoimmune rheumatic disease characterized by microvascular alterations, immunopathology, and widespread fibrosis involving various organs. It is considered difficult to treat due to several reasons: complex pathogenesis, heterogeneity, late diagnosis, limited treatment options for certain organ manifestations, lack of personalized medicine.

AREAS COVERED

This review presents the heterogeneity, survival and organ manifestations with their risk factors of systemic sclerosis and their current treatment options, while drawing attention to difficult-to-treat forms of the disease, based on literature indexed in PubMed.

EXPERT OPINION

Despite recent advances in the management of SSc over the last decades, the disease presents significant morbidity and mortality. Although available treatment protocols brought significant advancements in terms of survival in SSc-associated interstitial lung disease and pulmonary arterial hypertension, less success has been achieved in the treatment of Raynaud's phenomenon and digital ulcers and the results are modest in case of heart, gastrointestinal, and renal manifestations. There are patients who do not respond to treatment and deteriorate even with adequate therapy. They can be considered difficult-to treat (D2T) cases. We have created a possible score system based on the individual organ manifestations and highlighted treatment options for the D2T SSc category.

The management of axial spondyloarthritis with cutting-edge therapies: advancements and innovations

INTRODUCTION

Axial involvement in spondyloarthritis has significantly evolved from the original 1984 New York criteria for ankylosing spondylitis, leading to an improved understanding of axial spondyloarthritis (axSpA) as a disease continuum encompassing non- radiographic axSpA (nr-axSpA) and radiographic axSpA (r-axSpA). A clear definition for early axSpA has been established, underscoring the need for early intervention with biological and targeted synthetic drugs to mitigate pain, reduce functional impairment, and prevent radiographic progression.

AREAS COVERED

This review explores therapeutic strategies in axSpA management, focusing on biological and targeted synthetic therapies and recent advancements. Biologics targeting TNFα or IL-17 and targeted synthetic disease-modifying antirheumatic drugs (DMARDs) are primary treatment options. These therapies significantly impact clinical outcomes, radiographic progression, and patient-reported functional improvement.

EXPERT OPINION

AxSpA treatment has evolved significantly, offering various therapeutic options. Biological DMARDs, particularly TNFα inhibitors, have transformed treatment, significantly enhancing patient outcomes. However, challenges persist for patients unresponsive or intolerant to existing therapies. Emerging therapeutic targets promise to address these challenges. Comprehensive management strategies and personalized approaches, considering extra-articular manifestations and individual patient factors, are crucial for achieving optimal outcomes in axSpA management.

Deciphering difficult-to-treat psoriatic arthritis (D2T-PsA): a GRAPPA perspective from an international survey of healthcare professionals

Objectives

This study contributes to the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)'s effort to define 'difficult-to-treat' PsA (D2T-PsA), leveraging insights of healthcare professionals who are GRAPPA members. The primary objective is to inform GRAPPA's D2T PsA project, ensuring the consensus definition reflects clinical experience and expertise.

Methods

An online survey was conducted among GRAPPA's healthcare professionals managing PsA patients. The survey covered demographic details, structured questions, and open-ended queries to gather comprehensive insights into the experts' viewpoints.

Results

About 223 physicians completed the survey, comprising 179 (80.2%) rheumatologists and 40 (17.9%) dermatologists. The majority, 184 (82.5%), favoured establishing distinct definitions for D2T-PsA and complex-to-manage PsA (C2M-PsA). Furthermore, 202 (90.5%) supported a definition that includes objective inflammation signs (clinical, laboratory, imaging, among others). However, opinions varied on the criteria for prior treatment failures, with most (93, 41.7%) favouring a definition that includes at least one conventional synthetic disease-modifying anti-rheumatic drug and two or more biological- or targeted-synthetic-DMARDs with different mechanisms of action.

Conclusion

The survey reveals a majority opinion among GRAPPA experts favouring the differentiation between D2T-PsA and C2M-PsA, and the inclusion of objective inflammatory markers in these definitions. However, there is less than 50% agreement on the specific treatment failure criteria, particularly regarding the number of therapies needed to classify PsA as D2T. These findings suggest a need for continued discussion to reach a more unified approach in defining D2T-PsA, reflecting the complexity of the condition.

Unmet needs in axial spondyloarthritis. Proceedings of the French spondyloarthritis taskforce workshop

The progress observed over the last 30 years in the field of axial spondyloarthritis (axSpA) has not made it possible to answer all the current questions. This manuscript represents the proceedings of the meeting of the French spondyloArthitiS Task force (FAST) in Besançon on September 28 and 29, 2023. Different points of discussion were thus individualized as unmet needs: biomarkers for early diagnosis and disease activity, a common electronic file dedicated to SpA nationwide, a better comprehension of dysbiosis in the disease, a check-list for addressing to the rheumatologist, adapt patient reported outcomes thresholds for female gender, implementation of comorbidities screening programs, new imaging tools, in research cellular and multi omics approaches, grouping, at a nationwide level, different cohorts and registries, therapeutic strategy studies, consensual definition of difficult to treat disease and management, preclinical stage of the disease, mastering AI as a tool in the various aspects of research. These elements may represent a framework for the research agenda in axSpA for the years to come.

Characteristics of difficult-to-treat axial spondyloarthritis: Results of a real-world multicentric study

OBJECTIVE

The EULAR task force recently published the difficult-to-treat RA (D2T RA) definition, however, a definition of D2T axSpA is still lacking and limitations in this definition exist. The objectives were to study the characteristics of D2T axSpA patients using the EULAR definition and to study a subgroup of patients with a predefined more stringent definition including a temporal criterion.

METHODS

A multicentric retrospective study was performed. D2T axSpA was defined as failure of≥2 b/tsDMARDs with different mechanism of action. Very D2T axSpA was defined as failure of≥2 b/tsDMARDs in less than 2 years of follow-up. D2T and Very D2T axSpA patients were compared to non-D2T (nD2T) axSpA patients.

RESULTS

Three hundred and eleven axSpA patients were included: 88 D2T axSpA (28.3%) and 223 non-D2T (nD2T) axSpA (71.7%). Peripheral involvement was more prevalent in the D2T group (34.9 vs. 21.4%; P=0.015). BASDAI level at baseline was higher in the D2T group (63.7±16.5 vs. 58.8±14.7; P=0.015). Fibromyalgia was found to be more frequent in the D2T group vs nD2T group (P<0.001). Twelve patients (3.8%) were categorized as very D2T axSpA. Compared to nD2T, Very D2T patients had a higher CRP level at baseline (42.0±31.3 vs. 17.8±23.1; P=0.010). IBD prevalence at baseline was higher in the very D2T group (41.7 vs. 3.1%; P<0.001). None of the very D2T patients presented a fibromyalgia.

CONCLUSION

D2T axSpA was associated with higher disease activity, peripheral involvement, extra-musculoskeletal manifestations and fibromyalgia. Very D2T patients represented a minim proportion of patients after applying a more stringent definition including a temporal criterion of 2 years and might be independent from fibromyalgia.

A strategy towards disentangling treatment refractory from misdiagnosed axial Spondyloarthritis

Axial spondyloarthritis (axSpA) encompasses radiographic axial SpA (r-axSpA), formally designated as ankylosing spondylitis (AS) and non-radiographic axial SpA (nr-axSpA). The advent of MRI permitted the description of the "pre-radiographic" (nr-AxSpA) stage characterized by bone marrow oedema lesions, histologically an osteitis, not yet visible on X-rays. Most subjects with a diagnosis of nr-axSpA do not progress to r-axSpA and the risk of misdiagnosis of nr-axSpA is considerable because back pain related to malalignment, degenerative conditions or biomechanical stress including intense exercise may lead to positive MRI scans. Even when nr-axSpA or r-axSpA are accurately diagnosed only about 40-50% achieve the ASAS40 responses with licensed therapies. It is likely that spinal enthesitis/osteitis leading to structural damage and associated damage contributes to post inflammatory disc territory secondary pain responses. Things are complicated as the concept of refractory axSpA itself is not well defined since there is no gold standard test to capture the full burden of inflammatory disease and, in any event, MRI has not been systematically applied. Nevertheless, there is sufficient evidence to borrow from the refractory rheumatoid arthritis field to propose two types of refractory axial SpA- a persistent inflammatory refractory ax-SpA (PIRaxSpA) and non-inflammatory refractory ax-SpA (NIRaxSpA). Both axSpA refractoriness and misdiagnosis need careful considerations when evaluating treatment failure. The immunological basis for axSpA immunotherapeutics non-responses is still rudimentary beyond the knowledge of HLA-B27 positivity status, CRP elevation, and MRI bone oedema that represents osteitis being equated with responder status.

Difficult-to-treat axial spondyloarthritis is associated with psoriasis, peripheral involvement and comorbidities: results of an observational nationwide study

OBJECTIVES

To determine the cumulative incidence and identify the factors associated with difficult-to-treat axial spondyloarthritis (D2T-axSpA) in French patients newly benefiting from the French 'long-term illness' (LTI) social security scheme for axial spondyloarthritis (axSpA).

METHODS

This national cohort study was based on the French National Medico-Administrative Database, SNDS, which contains data on hospitalisation, LTI and outpatient care consumption. All French patients newly receiving LTI benefits for ankylosing spondylitis (AS) between 2010 and 2013 were included in the study. In France, LTI is required to access biological/targeted synthetic DMARDs (b/tsDMARDs). The follow-up period ended on 31 December 2018. So-called D2T-axSpA was defined as the failure of three b/tsDMARDs or of two b/tsDMARDs with different modes of action. Comorbidities and extra-musculoskeletal manifestations were identified using previously described algorithms. Characteristics were compared between patients with D2T-axSpA and patients with non-D2T-axSpA who had received at least one b/tsDMARD with bivariate and multivariate analysis using logistic regression. Incidence rates of major cardiovascular event (MACE) and death were compared using competitive risk analysis.

RESULTS

22 932 patients were included. 10 798 (47.08%) patients received at least one bDMARD. None received tsDMARD. During follow-up, 2115 patients were classified as having D2T-axSpA, representing 19.59% of patients who received at least one bDMARD. In multivariate analysis, D2T-axSpA was significantly associated with female gender, peripheral involvement, psoriasis, hypertension and depression (p<0.001 for each case). There was no difference in the incidence of MACE (p=0.92) or death (p=0.87).

CONCLUSION

D2T-axSpA affects one in five patients exposed to bDMARDs in this national cohort. D2T-axSpA is more common in women and patients with peripheral involvement and/or comorbidities.

Difficult to Treat and Refractory to Treatment in Psoriatic Arthritis

Psoriatic arthritis (PsA) is a complex and chronic inflammatory condition in which the achievement of the best possible disease control has been proposed as the treatment target, which includes the possibility of reaching remission in all disease domains. However, due to the complexity of this multidomain disease, some patients may still have high disease activity in one or more domain and a high burden of disease, potentially leading to various treatment changes and to difficulty with the overall management. In this paper, we overview the concept of patients with difficult-to-treat PsA and the concept of patients with refractory-to-treatment PsA by providing a distinction between these two concepts and the possible implication for the management of patients with PsA.